To display the usability status of interfaces configured for IP, use theshow ip interfacecommand in privileged EXEC mode.
show ip interface[type number][brief]
Syntax Description
(Optional) Interface type. type
(Optional) Interface number. number
(Optional) Displays a summary of the usability status information for each interface.
brief
Command Default The full usability status is displayed for all interfaces configured for IP.
Command Modes Privileged EXEC (#)
Command History Release Modification
This command was introduced. 10.0
The command output was modified to show the status of theip wccp redirect outandip wccp redirect exclude add incommands.
12.0(3)T
The command output was modified to display the status of NetFlow on a subinterface.
12.2(14)S
The command output was modified to display the status of NetFlow on a subinterface.
12.2(15)T
The command output was modified to identify the downstream VPN routing and forwarding (VRF) instance in the output.
12.3(6)
The command output was modified to show the usability status of interfaces configured for Multiprocessor Forwarding (MPF) and implemented on the Cisco 7301 and Cisco 7206VXR routers.
12.3(14)YM2
This command was implemented on the Supervisor Engine 720. 12.2(14)SX
This command was integrated into Cisco IOS 12.2(17d)SXB on the Supervisor Engine 2, and the command output was changed to include NDE for hardware flow status.
12.2(17d)SXB
show diameter peer through show object-group show ip interface
Modification Release
This command was integrated into Cisco IOS Release 12.4(4)T. 12.4(4)T
This command was integrated into Cisco IOS Release 12.2(28)SB. 12.2(28)SB
This command was integrated into Cisco IOS Release 12.2(33)SRA. 12.2(33)SRA
The command output was modified to display information about the Unicast Reverse Path Forwarding (RPF) notification feature.
12.2(31)SB2
The command output was modified to display information about the Unicast RPF notification feature.
12.4(20)T
This command was modified. The command output was modified to display information about the Unicast RPF notification feature.
12.2(33)SXI2
This command was modified. This command was implemented on the Cisco ASR 1000 Series Aggregation Services Routers.
Cisco IOS XE Release 2.5
Usage Guidelines The Cisco IOS software automatically enters a directly connected route in the routing table if the interface is usable (which means that it can send and receive packets). If an interface is not usable, the directly connected routing entry is removed from the routing table. Removing the entry lets the software use dynamic routing protocols to determine backup routes to the network, if any.
If the interface can provide two-way communication, the line protocol is marked "up." If the interface hardware is usable, the interface is marked "up."
If you specify an optional interface type, information for that specific interface is displayed. If you specify no optional arguments, information on all the interfaces is displayed.
When an asynchronous interface is encapsulated with PPP or Serial Line Internet Protocol (SLIP), IP fast switching is enabled. Ashow ip interfacecommand on an asynchronous interface encapsulated with PPP or SLIP displays a message indicating that IP fast switching is enabled.
You can use theshow ip interface briefcommand to display a summary of the router interfaces. This command displays the IP address, the interface status, and other information.
Theshow ip interface briefcommand does not display any information related to Unicast RPF.
Examples The following example shows configuration information for interface Gigabit Ethernet 0/3. In this example, the IP flow egress feature is configured on the output side (where packets go out of the interface), and the policy route map named PBRNAME is configured on the input side (where packets come into the interface).
Router# show running-config interface gigabitethernet 0/3 interface GigabitEthernet0/3
ip address 10.1.1.1 255.255.0.0 ip flow egress
ip policy route-map PBRNAME duplex auto
speed auto media-type gbic negotiation auto end
show diameter peer through show object-group
The following example shows interface information on Gigabit Ethernet interface 0/3. In this example, MPF is enabled, and both Policy Based Routing (PBR) and NetFlow features are not supported by MPF and are ignored.
Router# show ip interface gigabitethernet 0/3 GigabitEthernet0/3 is up, line protocol is up
Internet address is 10.1.1.1/16 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled Outgoing access list is not set
Inbound access list is not set Proxy ARP is enabled
Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled
IP fast switching on the same interface is disabled IP Flow switching is disabled
IP CEF switching is enabled
IP Feature Fast switching turbo vector IP VPN Flow CEF switching turbo vector IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled
Policy routing is enabled, using route map PBR Network address translation is disabled BGP Policy Mapping is disabled
IP Multi-Processor Forwarding is enabled IP Input features, "PBR",
are not supported by MPF and are IGNORED IP Output features, "NetFlow",
are not supported by MPF and are IGNORED
The following example identifies a downstream VRF instance. In the example, "Downstream VPN Routing/Forwarding "D"" identifies the downstream VRF instance.
Router# show ip interface virtual-access 3 Virtual-Access3 is up, line protocol is up
Interface is unnumbered. Using address of Loopback2 (10.0.0.8) Broadcast address is 255.255.255.255
Peer address is 10.8.1.1 MTU is 1492 bytes
Helper address is not set
Directed broadcast forwarding is disabled Outgoing access list is not set
Inbound access list is not set Proxy ARP is enabled
Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled
IP fast switching on the same interface is enabled IP Flow switching is disabled
IP CEF switching is enabled
IP Feature Fast switching turbo vector
show diameter peer through show object-group show ip interface
Downstream VPN Routing/Forwarding "D" IP multicast fast switching is disabled
IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Policy routing is disabled
Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabled
The following example shows the information displayed when Unicast RPF drop-rate notification is configured:
Router# show ip interface ethernet 2/3 Ethernet2/3 is up, line protocol is up
Internet address is 10.0.0.4/16 Broadcast address is 255.255.255.255 Address determined by non-volatile memory MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled Outgoing access list is not set
Inbound access list is not set Proxy ARP is enabled
Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is disabled IP Flow switching is disabled IP CEF switching is disabled IP Null turbo vector
IP Null turbo vector
IP multicast fast switching is disabled
IP multicast distributed fast switching is disabled IP route-cache flags are No CEF
Router Discovery is disabled
IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Probe proxy name replies are disabled Policy routing is disabled
Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabled
Examples
Input features: uRPF
IP verify source reachable-via RX, allow default 0 verification drops
0 suppressed verification drops 0 verification drop-rate Router#
The following example shows how to display the usability status for a specific VLAN:
Router# show ip interface vlan 1 Vlan1 is up, line protocol is up Internet address is 10.0.0.4/24 Broadcast address is 255.255.255.255 Address determined by non-volatile memory
show diameter peer through show object-group
MTU is 1500 bytes
Helper address is not set
Directed broadcast forwarding is disabled Outgoing access list is not set
Inbound access list is not set Proxy ARP is enabled
Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled
IP fast switching on the same interface is disabled IP Flow switching is disabled
IP CEF switching is enabled IP Fast switching turbo vector IP Normal CEF switching turbo vector IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Probe proxy name replies are disabled Policy routing is disabled
Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabled Sampled Netflow is disabled
IP multicast multilayer switching is disabled Netflow Data Export (hardware) is enabled
The table below describes the significant fields shown in the display.
Table 8: show ip interface Field Descriptions
Description Field
Shows whether the interface hardware is usable (up). For an interface to be usable, both the interface hardware and line protocol must be up. Virtual-Access3 is up
Broadcast address. Broadcast address is
Peer address. Peer address is
MTU value set on the interface, in bytes. MTU is
Helper address, if one is set. Helper address
Shows whether directed broadcast forwarding is enabled.
Directed broadcast forwarding
Shows whether the interface has an outgoing access list set.
Outgoing access list
Shows whether the interface has an incoming access Inbound access list
show diameter peer through show object-group show ip interface
Description Field
Shows whether Proxy Address Resolution Protocol (ARP) is enabled for the interface.
Proxy ARP
IP Security Option (IPSO) security level set for this interface.
Security level
Shows whether split horizon is enabled. Split horizon
Shows whether redirect messages will be sent on this interface.
ICMP redirects
Shows whether unreachable messages will be sent on this interface.
ICMP unreachables
Shows whether mask replies will be sent on this interface.
ICMP mask replies
Shows whether fast switching is enabled for this interface. It is generally enabled on serial interfaces, such as this one.
IP fast switching
Shows whether Flow switching is enabled for this interface.
IP Flow switching
Shows whether Cisco Express Forwarding switching is enabled for the interface.
IP CEF switching
Shows the VRF instance where the PPP peer routes and AAA per-user routes are being installed. Downstream VPN Routing/Forwarding "D"
Shows whether multicast fast switching is enabled for the interface.
IP multicast fast switching
Shows whether NetFlow is enabled on an interface. Displays "Flow init" to specify that NetFlow is enabled on the interface. Displays "Ingress Flow" to specify that NetFlow is enabled on a subinterface using theip flow ingresscommand. Shows "Flow" to specify that NetFlow is enabled on a main interface using theip route-cache flowcommand.
IP route-cache flags are Fast
Shows whether the discovery process is enabled for this interface. It is generally disabled on serial interfaces.
Router Discovery
Shows whether IP accounting is enabled for this interface and what the threshold (maximum number of entries) is.
IP output packet accounting show diameter peer through show object-group
Description Field
Shows whether compression is enabled. TCP/IP header compression
Shows the status of whether packets received on an interface are redirected to a cache engine. Displays "enabled" or "disabled."
WCCP Redirect outbound is disabled
Shows the status of whether packets targeted for an interface will be excluded from being redirected to a cache engine. Displays "enabled" or "disabled." WCCP Redirect exclude is disabled
NetFlow Data Expert (NDE) hardware flow status on the interface.
Netflow Data Export (hardware) is enabled
The following example shows how to display a summary of the usability status information for each interface:
Router# show ip interface brief
Interface IP-Address OK? Method Status Protocol
Ethernet0 10.108.00.5 YES NVRAM up up
Ethernet1 unassigned YES unset administratively down down
Loopback0 10.108.200.5 YES NVRAM up up
Serial0 10.108.100.5 YES NVRAM up up
Serial1 10.108.40.5 YES NVRAM up up
Serial2 10.108.100.5 YES manual up up
Serial3 unassigned YES unset administratively down down
The table below describes the significant fields shown in the display.
Table 9: show ip interface brief Field Descriptions
Description Field
Type of interface. Interface
IP address assigned to the interface. IP-Address
"Yes" means that the IP Address is valid. "No" means that the IP Address is not valid.
OK?
show diameter peer through show object-group show ip interface
Description Field
The Method field has the following possible values: • RARP or SLARP--Reverse Address Resolution
Protocol (RARP) or Serial Line Address Resolution Protocol (SLARP) request. • BOOTP--Bootstrap protocol.
• TFTP--Configuration file obtained from the TFTP server.
• manual--Manually changed by the command-line interface.
• NVRAM--Configuration file in NVRAM. • IPCP--ip address negotiatedcommand. • DHCP--ip address dhcpcommand. • unset--Unset.
• other--Unknown. Method
Shows the status of the interface. Valid values and their meanings are:
• up--Interface is up. • down--Interface is down.
• administratively down--Interface is administratively down.
Status
Shows the operational status of the routing protocol on this interface.
Protocol
Related Commands Command Description
Sets a primary or secondary IP address for an interface.
ip address
Enables VRF autoclassify on a source interface. ip vrf autoclassify
Specifies a source IP address to match to required route maps that have been set up based on VRF connected routes.
match ip source show diameter peer through show object-group
Description Command
Defines the conditions for redistributing routes from one routing protocol into another or to enable policy routing.
route-map
Enables VPN VRF selection within a route map for policy-based routing VRF selection.
set vrf
Displays the ARP cache, in which SLIP addresses appear as permanent ARP table entries.
show ip arp
Displays static and dynamic route maps. show route-map
show diameter peer through show object-group show ip interface